IP Multimedia Subsystem, more commonly known as IMS, is not a slam-dunk, according to a group of industry analysts who gathered in Washington, D.C., this month to discuss the advanced carrier services architecture.
The open standards-based blueprint defines how wireless and wireline IP networks should transport voice and data sessions even though the traffic travels over the public switched telephone network or a 3G wireless network. The architecture, which was discussed in depth by analysts at the FierceMarkets IMS Executive Summit, is designed to let carriers centralize application servers that all customers can reach.
The promise of IMS is that carriers will be able to deliver more services to more customers for less cost.
Only a handful of products available today support the standard, which makes it difficult to call IMS a definitive network architecture of the future, says Tom Valovic, program director for VoIP infrastructure at IDC. Carriers also will be challenged with the complexity of IMS, he says.
“IMS shouldn’t be considered a given,” Valovic says. “A lot...has to happen on the road to IMS’ success.”
All five analysts on one panel agreed the IMS standard is not complete, ready for the market or ready to support interoperability. They were asked to grade IMS on these three areas, and the technology received, on average, a solid D.
Not that there wasn’t optimism. “[IMS] will happen,” says Bob Johnson, senior analyst of the telecom practice at Venture Development, a market research firm. “But in what form? It will be a gradual adoption over time, over 24 months to 10 years.”
Service providers are testing the architecture. Ari Banerjee, senior analyst for telecom software strategies at consulting firm Yankee Group, says there are 100 IMS trials underway worldwide.
Cingular Wireless, a joint venture between AT&T and BellSouth (which AT&T is in the process of acquiring), announced last year it will deploy Lucent IMS gear as it upgrades its network to support the new architecture. Like its wireless joint venture, AT&T is committed to IMS. The carrier says it is replacing its Siemens Call Control Element server with an IMS Session Controller from Lucent this year, to support new VoIP features and services.
Verizon Wireless agrees with analysts that the IMS standard is incomplete, and the carrier is working on additions to make the specification more suitable. The wireless service provider has been working with Cisco, Lucent, Motorola, Nortel and Qualcomm for the past year to develop a framework called Advanced to IMS or A-IMS. The extensions are designed to better support non-Session Initiation Protocol devices, applications, services, end-to-end security and wireless VoIP QoS.
The industry also is trying to address the interoperability issue. The Global Multiservice Forum is planning an interoperability test in October that will span about 10 days. The event will be hosted by a handful of vendors and service providers, including BT, Nortel, NTT, Verizon and Vodafone.
According to the group’s Web site, the test will feature 27 vendors, including Alcatel, Cisco, Leapstone Systems, Lucent, MetaSwitch, Samsung and Tekelec.
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